chore: refactor the texture size constants

src/lib.rs

@@ -1,3 +1,7 @@
 pub use crate::mandelbrot::Bounds;
 pub use crate::mandelbrot::Mandelbrot;
+
+pub const TEXTURE_WIDTH: usize = 1280;
+pub const TEXTURE_HEIGHT: usize = 720;
+
 mod mandelbrot;

src/main.rs

@@ -1,5 +1,5 @@
 use bevy::{prelude::*, render::texture::TextureFormat};
-use mandelbrot::{Bounds, Mandelbrot};
+use mandelbrot::{Bounds, Mandelbrot, TEXTURE_HEIGHT, TEXTURE_WIDTH};
 use std::time::Instant;
 
 fn main() {
@@ -110,12 +110,12 @@ fn startup(
     mut textures: ResMut<Assets<Texture>>,
     mut materials: ResMut<Assets<ColorMaterial>>,
 ) {
-    let img_size = Vec2::new(Mandelbrot::width() as f32, Mandelbrot::height() as f32);
-    let img_buf = Mandelbrot::new().image().to_vec();
+    let texture_size = Vec2::new(TEXTURE_WIDTH as f32, TEXTURE_HEIGHT as f32);
+    let texture_data = Mandelbrot::new().image().to_vec();
 
     let texture_handle = textures.add(Texture::new(
-        img_size,
-        img_buf,
+        texture_size,
+        texture_data,
         TextureFormat::Rgba8UnormSrgb,
     ));
 

src/mandelbrot.rs

@@ -1,6 +1,10 @@
+use crate::{TEXTURE_HEIGHT, TEXTURE_WIDTH};
 use num_complex::Complex;
 use rayon::prelude::*;
 
+const DEFAULT_ITERATION_LIMIT: u32 = 64;
+const DEFAULT_BOUNDS: Bounds = Bounds::new((-2.5, 1.0), (-1.0, 1.0));
+
 pub struct Coordinate(usize, usize);
 
 impl Coordinate {
@@ -36,73 +40,59 @@ impl Bounds {
     }
 }
 
-const DEFAULT_MAX_ITERATIONS: u32 = 64;
-const DEFAULT_BOUNDS: Bounds = Bounds::new((-2.5, 1.0), (-1.0, 1.0));
-
 #[derive(Debug, Clone)]
 pub struct Mandelbrot {
-    texture_buffer: Vec<u8>,
+    frame_buffer: Box<[u8; (TEXTURE_WIDTH * TEXTURE_HEIGHT) * 4]>,
 }
 
 impl Mandelbrot {
-    const IMG_WIDTH: usize = 1280;
-    const IMG_HEIGHT: usize = 720;
-
     pub fn new() -> Self {
         Mandelbrot {
-            texture_buffer: vec![0; (Self::IMG_WIDTH * Self::IMG_HEIGHT) * 4],
+            frame_buffer: Box::new([0; (TEXTURE_WIDTH * TEXTURE_HEIGHT) * 4]),
         }
     }
 
-    pub fn width() -> usize {
-        Self::IMG_WIDTH
-    }
-
-    pub fn height() -> usize {
-        Self::IMG_HEIGHT
-    }
-
     pub fn image(&mut self) -> &[u8] {
-        let max_iters = DEFAULT_MAX_ITERATIONS as f64;
+        let limit_f64 = DEFAULT_ITERATION_LIMIT as f64;
 
-        self.texture_buffer
+        self.frame_buffer
             .par_chunks_mut(4)
             .enumerate()
             .for_each(|(i, buf)| {
-                let iters = Self::escape_time(i, DEFAULT_BOUNDS, DEFAULT_MAX_ITERATIONS);
-                let normalized_iters = iters / max_iters;
+                let iterations = Self::escape_time(i, DEFAULT_BOUNDS, DEFAULT_ITERATION_LIMIT);
+                let normalized_iters = iterations / limit_f64;
 
                 let h = normalized_iters * 350.0;
-                let v = if iters == max_iters { 0.0 } else { 1.0 };
+                let v = if iterations == limit_f64 { 0.0 } else { 1.0 };
                 buf.copy_from_slice(&Self::hsv_to_rgb(h, 1.0, v));
             });
 
-        &self.texture_buffer
+        self.frame_buffer.as_ref()
     }
 
-    pub fn scaled_image(&mut self, bounds: Bounds, max_iterations: u32) -> &[u8] {
-        self.texture_buffer
+    pub fn scaled_image(&mut self, bounds: Bounds, limit: u32) -> &[u8] {
+        self.frame_buffer
             .par_chunks_mut(4)
             .enumerate()
             .for_each(|(i, buf)| {
-                let max_iters = max_iterations as f64;
+                let limit_f64 = limit as f64;
 
-                let iters = Self::escape_time(i, bounds, max_iterations);
-                let normalized_iters = iters / max_iters;
+                let iterations = Self::escape_time(i, bounds, limit);
+                let normalized_iters = iterations / limit_f64;
 
                 let h = normalized_iters * 350.0;
-                let v = if iters == max_iters { 0.0 } else { 1.0 };
+                let v = if iterations == limit_f64 { 0.0 } else { 1.0 };
                 buf.copy_from_slice(&Self::hsv_to_rgb(h, 1.0, v))
             });
 
-        &self.texture_buffer
+        self.frame_buffer.as_ref()
     }
 
-    fn escape_time(i: usize, bounds: Bounds, max_iterations: u32) -> f64 {
-        let point = Coordinate::new(i % Self::IMG_WIDTH, i / Self::IMG_WIDTH);
+    fn escape_time(i: usize, bounds: Bounds, iteration_limit: u32) -> f64 {
+        let point = Coordinate::new(i % TEXTURE_WIDTH, i / TEXTURE_WIDTH);
         let c = Self::coords_to_complex(point, bounds);
 
-        Self::count_iterations(c, max_iterations)
+        Self::count_iterations(c, iteration_limit)
     }
 
     #[inline]
@@ -137,27 +127,27 @@ impl Mandelbrot {
         [r, g, b, a]
     }
 
-    fn count_iterations(c: Complex<f64>, max_iterations: u32) -> f64 {
+    fn count_iterations(c: Complex<f64>, maximum: u32) -> f64 {
         let mut z: Complex<f64> = Complex::new(0.0, 0.0);
-        let mut num_iters: u32 = 0;
+        let mut count: u32 = 0;
 
         loop {
             if z.norm_sqr() > 4.0 {
                 break;
             }
 
-            if num_iters >= max_iterations {
+            if count >= maximum {
                 break;
             }
 
             z = (z * z) + c;
-            num_iters += 1;
+            count += 1;
         }
 
-        if num_iters < max_iterations {
-            (num_iters as f64 + 1.0) - z.norm().ln().ln() / 2f64.ln()
+        if count < maximum {
+            (count as f64 + 1.0) - z.norm().ln().ln() / 2f64.ln()
         } else {
-            num_iters as f64
+            count as f64
         }
     }
 
@@ -173,7 +163,7 @@ impl Mandelbrot {
         // const X_MIN: f64 = -2.5;
         // const X_MAX: f64 = 1.0;
 
-        bounds.0 + ((bounds.1 - bounds.0) * (x as f64 - 0.0)) / Self::IMG_WIDTH as f64 - 0.0
+        bounds.0 + ((bounds.1 - bounds.0) * (x as f64 - 0.0)) / TEXTURE_WIDTH as f64 - 0.0
     }
 
     #[inline]
@@ -181,6 +171,6 @@ impl Mandelbrot {
         // const Y_MIN: f64 = -1.0;
         // const Y_MAX: f64 = 1.0;
 
-        bounds.0 + ((bounds.1 - bounds.0) * (y as f64 - 0.0)) / Self::IMG_HEIGHT as f64 - 0.0
+        bounds.0 + ((bounds.1 - bounds.0) * (y as f64 - 0.0)) / TEXTURE_HEIGHT as f64 - 0.0
     }
 }